Toyo Ink Mfg. Co., Ltd.

Yuusaku Ide

Takuya Kotani

Osamu Shiromaru

Toshio Oshiba

A process for the production of a &#x3b2; type copper phthalocyanine pigment having an average primary crystal diameter of 80&#xb1;40 nm and a primary crystal aspect ratio of 2.0&#xb1;1.0 and having a crystallite diameter of 22&#xb1;5 nm in the direction perpendicular to a monoclinic &#x3b2; (200) plane, a crystallite diameter of 27&#xb1;5 nm in the direction perpendicular to a &#x3b2; (001) plane and a crystallite diameter of 15&#xb1;5 nm in the direction perpendicular to a &#x3b2; (010) plane, which process comprises, dry-milling a crude copper phthalocyanine having a purity of 97 to 100% and a primary crystal diameter of 0.5 to 100 &#x3bc;m at 180 to 50&#xb0; C., to prepare an &#x3b1;/&#x3b2; mixed crystal type copper phthalocyanine having an a ratio of 5 to 35%, and treating the dry-milled product in a water-miscible organic solvent.

Growing community of inventors

Tokyo, Japan

Yuusaku Ide